Field-coil lead shield



. Aug. 25, 1925. 1 551,290

G. M. EATON FIELD 0011. LEAD SHIELD Filed Oct. 6, 1920 INVENTOR Qeor 42m. 5 ATi'ORNEhY WITNESSES:

Patented Aug. 25, 1925.

UNITED STATES PATENT, OFFICE. q

GEORGE M. EATON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T WESTINGHOUSE ELECTRIC 8: MANUFACTURING COMPANY, A. CORPORATION OF PENNSYLVANIA.

FIELD-COIL LEAD SHIELD.

Application filed October 6, 1920. Serial No. 415,210.

To all whom it may 00mm.-

Be it known that I, GEORGE M. EATON,

a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Field-Coil Lead Shields, of which the following is a specification.

My invention relates to fieldunagnet coils and it has particular relation to shields for the protection of the connect-ions between the coil and the leads thereof.

Heretofore, it has been customary, in the construction of coils of the above indicated character, to solder the leads to the field coil straps and to wrap the coil and soldered connection with tape. The structure was then dipped into a liquid insulating and water-proofing compound which was allowed to dry and harden to form a protective coating over the entire coil.

Owing, however, to the irregular configuration of the parts, it has been very di'. cult to obtain an even and water-tight application of the tape in the vicinity of the connection of the lead with the coil, as the tape extended across from the higher portions and formed pockets or recesses between the tape and the coil which necessitated packing them with oakum or other suitable material to effect a water-tight joint.

It has been observed that,notwithstanding the extreme care with which the tape has been appliedby the above method, leaks frequently developed in the vicinity of the connection which permitted water, that occasionally flowed down the leads through the openings in the motor frame, to have access directly into the coil which resulted in the establishing of short-circuits and the consequent damage to the machine. Furthermore, the above method was slow and expensive, as considerable time and skill was required to effect a proper application of the tape and packing.

One of the objects of my invention is to provide a shield of the above indicated character that may be quickly and easily applied to the leads of a field coil and that is of such shape as to conform to the exterior configuration of the coil in the vicinity of the connection of the leads therewith and which renders possible an even distribution of the tape thereon and an easy and safe sealing of all access to the objectionable pockets therebetween.

lVith such objects in view, as well as other advantages which may be incident to the utilization of the improvement, the inven tion consists in the parts and combinations thereof hereinafter set forth and claimed, with the understanding that the several necessary elements constituting the same may be varied in proportion and arrangement without departing from the nature and scope of the invention.

In order to make the invention more clearly understood, means are shown in the accompanying drawings for carrying the same into practical effect, without limiting the improvements, in their useful applications, to the particular constructions which, for the purpose of explanation, are made the subject of illustration.

In the accompanying drawings:

Figure 1 is a plan View of a shield for field coil leads constructed in accordance with my invention;

Fig. 2 is a view in section on line IIII of Fig. 1, showing the shield as applied to a field coil, and

Fig. 3 is a view in end elevation of the structure shown in Fig. 2.

Referring to the drawings, 1 indicates a field-magnet coil, of any preferred construction, and having the usual terminals 2 and 3 secured thereto, as at 4, in any preferred manner. A shield 5, preferably in the form of an integral molded housing, encloses the connection of the leads 2 and 3 to the coil 1. The shield 5 is preferably formed of a phenolic condensation product having woven or reticulated reinforcing laminations 9 imbedded therein. The shield 5 is provided with a plurality of oppositely extending tubular projections 6 and 7 through which the leads 2 and 3 may respectively project.

After the shield 5 has been positioned upon a coil, as illustrated in Fig. 2 of the drawings, tension may be so exerted upon the leads in opposite directions as to force the shield into close contact with the areuate periphery of the coil. The coil and shield may then be taped by hand in the usual manner and a suitable water-proof packing 8 may be inserted around the leads 2 and 3 within the tubular projections 6 and 7 to seal the same.

\Vhen the junctions of coil terminals and the corresponding leads are enclosed in the manner set forth above, the coils are effectually protected from water which might otherwise enter the coil structure and cause damage by reason of short circuits.

I claim as my invention 1. A shield for coil leads comprising a housing adapted to conform to the configuration of the periphery of a coil and be secured thereto, said housing being provided with apertures through which the coil leads are adapted to project.

2. A shield for coil leads comprising an integral housing adapted to incase the juncture of a lead with its coil, and provided with apertures through which said lead may project.

3. A coil lead shield comprising a molded housing adapted to incase the juncture of a field coil and its leads, and adapted to be brought into close contact with said coil, said housing being provided with oppositely extending tubular projections, through which said leads are adapted to project.

t. A coil-lead shield comprising an integral housing of insulating material provided with a flanged portion adapted to be secured to a coil and a plurality oi tubular portions disposed in different planes and extending in opposite directions with respect to each other through which the coil leads are adapted to project.

In testimony whereof I have hereunto subscribed my name this 29th day of September, 1920.

GEORGE M. EATON. 

